John was a native of Capistrano, in Italy. He became a Franciscan and was one of the great organizers of the struggle against the Mohammedans in the 15th century, when they threatened to overrun the whole of Europe. Mohammed II had taken Constantinope and was already marching against Belgrade, when Pope Callixtus III called St. John to preach the crusade; assisted by the Hungarian John Hunyadi, he gathered a strong Christian army, which defeated the Turks in the great battle of Belgrade (1453). He died in 1456.

The Vatican Congregation for Divine Worship has approved the insertion of the optional memorial of St. John Paul II in the proper calendar of the dioceses of the United States for today.

According to the 1962 Missal of St. John XXIII the Extraordinary Form of the Roman Rite, today is the feast of St. Hilarion, who was born of pagan parents near Gaza in Palestine toward the close of the third century. He studied at Alexandria and became a Christian at the age of 15. Following the example of St. Anthony in Egypt, Hilarion resolved to become a hermit in the desert, and Anthony himself trained the youth. He gave all his possessions to the poor, and became the father of monasticism in Palestine and Syria, famous for his miracles and sanctity. He lived to be over 80, dying on the island of Cyprus in 372.